Methods of grouting tile

ABSTRACT

An improved method for grouting tile which comprises applying a property-improving material subsequent to trowelling of the grouting composition so as to advantageously modify the working properties and/or final performance properties of the grout initially used and supplied in the container.

United States Patent 1191 Bernett Feb. 18, 1975 1 1 METHODS OF GROUTING TILE [56] References Cited [75] Inventor: Frank E. Bernett, Yardley, Pa. UNITED STATES PATENTS 1 1,731,162 10/1929 Ficklen .5 52/744 173] Asblgnee' g? i Amema 2,853,928 9/1958 Reardon 264/79 3.140566 7/1964 Wagner .3 52 744 [33] Filed; Dec 1973 3,381,066 4/1968 Lowe 264/261 121] 422835 Primary Examiner]ohn E. Murtagh Related US. Application Data [60] C0ntinuati0n-in-part of Ser. No. 363,858. May 25, 1 1 A T 1973, abandoned, wh1ch 1s, a d1v1s10n 01 Ser. No. An improved method for grouting 16 which 130006 March 1971 prises applying a property-improving material subsequent to trowelling of the grouting composition so as [2%] }LS.CCII. 52/7lg14af5ig383 to advantageously modify the working properties gi' 52/74 /or final performance properties of the grout initially used and supplied in the container.

16 Claims, N0 Drawings METHODS O GROUTING TILE CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part application of U.S. application Ser. No. 363,858 filed May 25, 1973, now abandoned which is a divisional application ofU.S. Ser. No. 130,006 filed Mar. 31, 1971, now U.S. Pat, No. 3,735,545.

BACKGROUND OF THE INVENTION This invention relates to an improved method of grouting tile. More particularly, it relates to the process of applying a material to an already trowelled tile grout in order to impart properties different than those of the original grouting composition.

Formulation of a new ceramic tile grout is a difficult, time consuming operation that more than not ends in practical failure. Although there now exists numerous acceptacle grouting compositions, the ultimate test is not simply the observance of good performance properties. A formulation must be packagable in relatively small containers (up to 5 gallons); it must have long storage life; it must be trowellable so the mechanic can spread it easily on the tiled surface; the excess must be easily removable from the surface without the aid of harmful cleaning fluids; it must retain its position in the final joint without sagging, pinholing or shrinking; the time required to effect proper installation should be reasonable; and the grouted tile in final form must have certain desirable properties such as hardness, stainresistance, water impermeability, chemical resistance, acceptacle color and durability.

Final performance properties are invariably sacrificed, according to current formulation practices, in order to achieve ease of application for the ceramic tile grout. Thus, the consumer is unfortunately denied the optimum performance of which grouting materials are capable. The present invention is intended to remedy that condition.

SUMMARY OF THE INVENTION Accordingly, this invention is concerned with an improved method of grouting tile which permits the tile installer or tile mechanic to beneficially modify an already trowelled ceramic tile grout composition by applying a property-improving material.

The typical procedure for grouting tile comprises the following steps;

a. trowelling the grouting composition on a substrate and into the joints between the tile, said tile placed on said substrate;

b. removing excess grout from the tile faces;

c. washing the tile surface and shaping the joints to the desired configuration; and

d. cleaning the tile once the tile face is dry.

The materials disclosed herein are applied any time after step (a) in the form of a solution, partial solution, suspension dispersion, emulsion, etc. and are usually administered as a spray. Whenever possible, a solution applied as a liquid by means of a spray gun is preferred. If the material itself is a liquid, it is also within the teachings of this invention to apply it directly without the assistance of a diluent or solvent.

A principal advantage of the hereindisclosed process is that dramatic changes can be made in rheology of a grout after it is placed between tiles. In most if not all instances, it is unreasonable to incorporate the property-improving materials into the grout prior to trowelling. The reason is that properties desirable for trowel ling are different from those desirable in the washing and shaping stages. In addition, storage life of the canned grout would be nil with some of the materials found beneficial to washing and clean-up if they were in the original formulation. However, once the grout has been trowelled and the usual initial stages of grouting have occurred, certain damaging reactions can be tolerated or minimized. More importantly, the materials can then be applied to provide unexpected and unusual beneficial' results. In large scale commercial applications, the hereindisclosed novel method speeds up the grouting operation by as much as 25 percent. This is a very important consideration when trying to minimize expensive labor costs.

Although the exact mechanism in which these property-improving materials function is not fully understood at the present time, it is known that they act to accomplish one or both of the following:

I. firming the grout sufficiently so that when the washing or cleaning step is preformed, the grouting composition is not undesirably removed or wiped away, and/or 2. forming a dustable haze which is easily removed. The usual technique is to wipe hard necessitating a difficult physical manipulation or by rewetting and then sponging with, for example, a wet cloth.

The type of grouting compositions which are subject to improvement by the hereindisclosed process include (I) grout compositions containing film-forming, water resistant polymers such as polymer emulsions having a solids content of at least 40 percent capable of coalescing upon the loss of water from the grouting composition; (II) grout compositions containing waterdispersible, room temperature, cross-linkable polymers combined with a water-insoluble filler; (III) Latex- Portland cement grouts and mortars; and (IV) nonaqueous hardened epoxy grouts.

Depending on the grouting composition used, particular property-improving materials will be utilized. However, in many instances, certain materials can be effectively used for all types of grouting formulations, whereas with others, only one type of formulation may be effectively treated.

Morover, it is possible and within the purview of this invention to combine more than one of the hereindisclosed property improving materials. Of course, a restriction may be imposed on the physical nature of the mixture. For instance, a fatty acid will not dissolve in an aqueous solution. In those instances, the problem is easily solved by applying two separate formulations one right after the other or working with emulsions of the immiscible materials.

The following is a tabulation of the effective property improving materials of this invention together with the type of grouting formulation which is effectively treated by those materials:

Property Improving Material Grouting Formulation described above Types I. II and Ill described above (3) tri-n-butyl phosphate, tall oil fatty acid. acetone. methyl -Continued Property Improving Material Grouting Formulation ethyl ketone, glycerin, mineral oil, mineral spirits and mix turcs thereof Cross linking Catalyst Hygroscopic agent Type 11 Types 1, II and Ill (6) Coalescing accelerator Types I, II and Ill (7) Water-insoluble fatty acid Types 1, II and [II have 6-20 carbons (8) Antifoaming agent Types 1. II. III and IV (9) Wetting inhibitor Type IV DETAILED DESCRIPTION OF THE INVENTION Examples of the types of grout compositions which are advantageously treated by the process'of this invention include:

A. An aqueous mortar composition havinga viscosity in the range of 10,000 cps to 4,000,000 cps* comprising a film-forming, water resistant polymer and a waterinsoluble filler.

*The Brookficld helipath viscosity whcn measured at 2.5 rpm.

B. Latex-Portland cement type grouts.

C. Nonaqueous epoxy grouts.

A highly preferred embodiment of type A relates to those wherein said polymer, in the form of a water resistant polymer emulsion having a solids content of at least 40percent, is capable of coalescing upon the loss of water from the grouting composition. Although the mechanism by which the aforesaid coalescence takes place is not fully understood, it is distinguishable from a cross-linking mechanism as described hereinafter. It is known, however, that as the grout loses water and then hardens by coalescence of the polymer emulsion particles, there is formed a grout, which is substantially more stain resistant than ordinary Portland cement type grouts.

The improved grouting compositions which incorporate these coalescent-type polymers, usually as aqueous emulsions, have a viscosity of 50,000 to 4,000,000 cps, a total solids content to 88 percent and a volatile component content of from 8 percent to 20 percent which comprises an admixture of a water-resistant polymer emulsion, having a solids content of at least 40 percent with the maximum content not in excess of about 75 percent and a water insoluble filler.

Another highly preferred embodiment of the aforedescribed compositions are those in which said polymer is a film-forming, water dispersible, room temperature cross-linkable polymer and the cross-linking process is assisted by the addition of a cross-linking agent or a catalyst. When an acidic catalyst is utilized, it is further preferred to include an activating agent.

Preferred amounts of each component are as follows: It is understood, however, that components A, B and F are essential components whereas the inclusion of C, D and E are preferred embodiments.

Acidic catalyst 5090% by Weight 003-2071 by weight -Continued catalytic amounts an amount sufficient to permit substantial cross-linking (at least a stoichiomctric equivalent amount) 815/: by weight Acitivating agent Cross-linking agent F. Water Coalescence-type polymers and cross-linkable polymers of the type referred to above and their use in grouting compositions are described in detail in applications Ser. No. 105,068, filed Jan. 8, 1971, now US. Pat. No. 3,706,696; Ser. No. 105,109, filed Jan. 8,

1971, now abandoned and prosecuted as a copending continuation application Ser. No. 304,727, filed Nov. 8, 1972; and copending application Ser. No. 124,559, filed Mar. 15, 1971, all having a common assignee.

Latex-Portland cement type grouts designated as III above are commonly used and known in the trade and consist ofa mixture of Portland cement, polymer emulsion and minor organic and inorganic additives.

Nonaqueous epoxy grouts are suitably described in US. Pat. Nos. 3,140,566, 3,183,198, 3,209,500. 3,212,946,. 3,287,302, 3,311,515, 3,348,988, 3,396,l38, 3,396,140 and 3,396,141.

By the term method of grouting tile," is meant the art recognized procedure for setting and grouting tile. In grouting, an assembly containing a plurality of ce ramic tile in edge to edge relationship with spaces between the tiles is prepared and spaces between the tile filled with the compositions of this invention. When used to set and grout ceramic tile, the compositions form a hard, adherent, chemically resistant bond between the backs of said ceramic tile and the substrate.

Normal grouting comprises the steps of:

l. trowelling the grout on the wall and into the joints between the tiles;

2. removing excess grout from the file faces;

3. washing the tile surfaces and shaping the joints as desired with a sponge or similar soft pad; and

4. wiping the tile clean with a dry cloth or similar materal.

The process improvement of this invention is concerned with the application of a property improving material to the grout which has been trowelled so that the resulting product is easier to handle during installation or demonstrates final performance properties above those of the original grout or both.

Although the manner in which the propertyimproving material is applied is' not critical, it is preferred to spray a liquid onto the areas to be treated making certain that the selected areas are completely covered.

The application can be effected any time after step (1) and prior to step (4) shown above.

The particular property improving materials can be categorized into groups as follows:

1. Aqueous solution of a polyvalent metal salt or NH CI 2. Group II metal hydroxide 3. Tri-n-butyl phosphate, tall oil fatty acid, acetone, methyl ethyl ketone, glycerin, mineral oil, mineral spirits and mixtures thereof 4. Cross-linking agent or catalyst 5. Hygroscopic agent 6. Coalescing accelerator 7. Water-insoluble fatty acid having 6-20 carbons 8. Antifoaming agent 9. Wetting inhibitor Regarding group (1), any polyvalent metal salt can be used, preferably derived from a metal of Groups ll and Ill. Illustrative salts include calcium chloride, magnesium chloride and aluminum chloride. It is found that ammonium chloride is highly effective and is included within this category. A preferred concentration is from 1 percent by weight to saturation, with a 3 to 9 percent by weight solution most preferred.

Group (2) above comprises aqueous mixtures of Group II metal hydroxides. Typical examples include aqueous magnesium hydroxide, calcium hydroxide, barium hydroxide and zinc hydroxide. The preferred concentration for these materials is from 0.01 percent to to a saturated solution.

Group (3) includes those substances shown. Since these substances are liquids, it is possible and possibly preferrable to administer them directly without incorporating them into a diluent or solvent. However, should a more fluid material be desired, any unreactive diluent may be added in typically used amounts to form a solution or emulsion which may then be applied.

Group (4) consists of cross-linking agents or catalysts. The particular catalyst or cross-linking agent utilized depends on the particular polymer in the system. For instance, to cross-link an epoxy resin, a crosslinking agent or hardening agent is preferred. Any cross-linking agent known in the art of polymerization is contemplated herein the only requisite is that it is capable of causing interaction between the functional groups on the polymer chains to permit the formation of a chemical bond. v

In the situation where a catalyst is used to assist in the cross-linking process, the catalyst material is preferably an acidic catalyst and, in particular, inorganic and organic salts, organic acids and amine acid-addition salts. Specific examples include ammonium chloride, magnesium chloride, ammonium sulfate, ammonium bromide, ammonium thiocyanate, dichloroacetic acid, ptoluene sulfonic acid, citric acid, oxalic acid, sulfamic acid and Z-methyl-2-aminopropanol-1-hydrochloride. When the catalyst is an acidic cataly'st'of the type just described, it is sometimes desirable to include an activating agent to accelerate setting. A typical activating agent is formaldehyde; however, those known in the art of polymerization are within the purview of this invention. The amount of said activating agent will generally be in catalytic quantities.

Group (5) consists of hygroscopic agents. Illustrative examples include: glycerin, calcium chloride, amines, urea, certain nitrates, etc. These substances comprise any material known in this particular field of study which retain or take up moisture.

Group (6) refers to coalescing accelerators. Typical examples are: butyl acetate, tri-n-butyl phosphate, acetone, certain divalent metal ions like calcium, magnesium, strong acids or strong bases, polyacrylic acid, polyacrylamide and water soluble phosphates.

Group (7) comprises water-insoluble fatty acids having 6 to carbon atoms. A typical example of such an acid is tall oil fatty acid.

Group (8) consists of antifoaming agents such as trin-butyl phosphate, fatty acids, waxes, oils, etc. This group of substances contemplates any antifoaming agent known in this particular art.

Group (9) comprises wetting inhibitors such as tri-nbutyl phosphate when used in epoxy grout.

It has been indicated that each type can be used separately or in combination. Furthermore, the particular material chosen will depend on the grouting composition to be improved, adjusted or frustrated.

This invention facilitates automatic or machine grouting of ceramcic tile. It is common now for the craftsman to get sheets of tiles together by flexible tabs or hinges. This reduces labor over setting one at a time. Machine grouting can further reduce labor. The property-improving material almost immediately firms up or flocculates the freshly affixed grout enabling the machine to almost immediately clean up and finish the grouting application.

Of particular interest in the present invention are the property improving materials found useful for the Latex-Portland cement grouts and mortars.

As noted earlier, the exact reaction mechanism in which these materials function is not fully understood. However, recent investigation indicates that the improving materials specifically attack the latex portion of the Latex-Portland cement compositions. However, there is evidence that those materials react with the cement as well, but it is believed the reaction with the latex portion causes the improved properties relating to washability. Because this reaction attacks the latex, it is not possible to add the improving materials prior to grouting. The improving material if added to the composition in sufficient quantities prior to grouting would cause the grout to stiffen, cause it to lump and make its application, for example, in the joint between ceramic tiles, almost impossible.

The latex normally functions in the composition as an emulsion or vehicle for the cement. When water is re moved, e.g., by evaporation, the latex coalesces and becomes a binder in the grout composition. While this is advantageous for the grout while in the joints, it is exactly what is detrimental in the cleaning and washing steps on the surface of the tile. The property-improving materials, when applied according to the present invention, have the specific ability of preventing the latex from forming a film. On of the key attributes is that it only affects the latex of the grout composition on the surface of the tiles.

The dustable haze as described earlier is caused by the destruction of the latex emulsion on the surface of the grout composition. It should be noted that a dustable haze normally forms when Portland cement grouts are used without latex being present. Therefore, the improving material actually removes the effectiveness of the latex from the tile surface. Although some haze forms on the surface of latex-portland cement mortars, even without the use of an improving material, the haze that forms strongly adheres to the tile surface making polishing of the surface a difficult if not impossible task.

The materials found most effective in improving washability of the latex-portland cements include those designated above as Group (6) coalescing accelerators of which are preferred polyacrylic acid, polyacrylamides and soluble phosphates.

The polyacrylamides found useful in the present invention are those commercially availible within the range of molecular weight of 30,000 to 6,000,000. However, the higher molecular weight of polyacrylamides are preferred. The polyacrylamides may be anionic, catonic, or nonionic in character and the character of the polyacrylamides may be modified through reactions involving the amide groups. Examples of such polyacrylamides include those manufactured by the Hercules Chemical Co: RETEN A-l a high molecular weight polyacrylamide of anionic character having a viscosity in a 1 percent solution of 1000-1500 cps; RETEN-ZOO, a non-ionic high molecular weight polyacrylamide having a viscosity of 300-500 cps in a l percent solution; RETEN2l0, a high molecular weight cationic polyacrylamide having a viscosity in a 1 percent solution of 1300-1800 cps. Aqueous solutions of polyacrylamides have been found useful where the polyacrylamide is present in the solution in the range of .02 to 1 percent by weight. Mixtures of the various polyacrylamides have also been found very effective.

A wide range of molecular weights have also been found useful for polyacrylic acid as well. Although molecular weight from 8,000 to 20,000 are effective, the higher molecular weights from 16,000 to 20,000 are preferred. A factor which must be considered is whether the viscosity of the improving material in aqueous solution will enable it to be applied easily to the grout, for example by spraying or by sponge application. This consideration concerns polyacrylic acids as well as the other materials contemplated herein. Aqueous solutions containing from 0.5 to 5 percent polyacrylic acid by weight have been found useful.

The water soluble phosphates include dibasic phosphates which are water soluble. As the dibasic phosphates do not have a strong effect on the viscosity of the composition, a wide proportional range has been found useful, of about 1 to 12 percent by weight. An'

example of a water soluble dibasic phosphate found effective is ammonium dibasic phosphate.

EXAMPLE I Part A A polymer emulsion based grout on the following formula was applied to the surface of glazed wall tile set in a common ceramic tile adhesive on a gypsum wallboard wall:

' AC-33 is an acrylic latex polymer emulsion based on a major amount of ethyl acrylate and a minor amount of methyl methacrylate in proportions to provide a glass transition temperature of 12C. sold commercially by Rohm and Haas.

The grout was spread over the entire tile area using a smooth rubber trowel and properly forced into the vertical and horizontal joints between the tile. After the joints were filled, the excess grout was removed using the edge of the trowel as a squeegee. After a short drying period, the remaining grout film and excess material filling the joints was wetted with a sponge and water, and the wall surface scrubbed lightly to loosen and remove the excess grout. Extreme care was taken to avoid too much water which would run down the vertical joints between tile and wash away grout that should remain. The sponge was used to wet polish the tile surface and dress the joints to a smooth finish and even contour. When the wall looked clean, sponging was stopped and the wall left to dry before final cleanup. As the wall dried, a haze formed over the tile surfaces. A dry cloth polishing rag was used to wipe off the dry haze. It was handled carefully and the haze came away, but took much work. The haze'was hard on the tile by the time the last half of the wall was being worked and the wall had'to be rewetted with a sponge to soften the haze.

The finished wall looked fine, but on close inspection it could be seen that vertical grout joints were deeper than ideal, a condition called washed-out" by the trade and the horizontal joints had creases in their center line in many instances. The whole operation took 25 minutes of working time and was tiring during the difficult polishing stages.

Part B An identical wall surface and identical grout were used to duplicate the experience described in Part A of this example, except that the method of this invention was used to apply a 6 percent solution of calcium chloride in water to the wall at a critical time.

After the grout was spread on the wall and forced into the joints, the wall was squeegeed as before. At this point in the operation, the solution of calcium chloride was sprayed on the wall in sufficient quantity to just wet it all without it running down the wall surface. Immediately after the spraying. the sponging and dressingof the joints was done. It was obvious that the grout in joints was firm and not easilywashed away by excess water, so much less care and more speed could be used.

When the cleaning was done in the normal way, it was found that the haze that formed on the tile easily dusted away with the dry cloth. In fact, a small area left overnight dusted away the next morning as easily as the day before.

The finished wall looked very good. Vertical joints were full as desired and the horizontal joints were smooth and even without creases. The whole operation took only 20 minutes, a savings of 20 percent of the time and, as noted, resulted in a superior finished job.

In this example the effects of the sprayed on solution were (1) firming of the grout in the joint which allowed faster'washing and dressing and (2) some effect on the dried haze which made it easy to remove in a simple manner.

It should be noted that an attempt to add calcium chloride directly to the grout before it was applied to the wall caused it to thicken so that it could not be trowelled and overnight it became hard in the can.

EXAMPLE [I Other chemicals were checked for .their ability to produce either of the beneficial effects on the polymer emulsion grout described in Example 1.

effect on firm- -Continued effect on firm Chemical ing of joints effect on haze to 72 hrs. dusting improved firming Mixture of 6% aluminum good firming chloride and 6% magnesium chloride effect up to 72 hrs.

EXAMPLE III An epoxy grout of the water cleanable type described in U.S. Pat. No. 3,212,946 was used to grout ceramic wall tile. The procedure is similar to that of Example I except that the grout residue on the surface of the tile after trowelling it on the tile surface and into the joints is not so easily dispersed in water. Considerable scrubbing with the sponge is required to dislodge the sticky grout from the tile. A constituent of the nonaqueous grout, however, will emulsify in water and then act as an emulsifier for the rest ofthe system so that complete removal of the excess grout is eventually effected. During the process, considerable foam is generated, which is undesirable, and the epoxy resin resists separation from the tile surface. When cleaning was finally com plete, bubbles of foam have to be removed or broken from the surface of the grout in the joints between tile, and the labor of the operation is considerable.

In a second attempt of the same grouting operation according to the method of this invention, tri-n butyl phosphate was sprayed lightly in the panel after the squeegee operation. Subsequent washing with water was much easier mainly because of the substantial reduction of foam during the scrubbing operation but also because the tri-n-butyl phosphate appears to lift the epoxy resin away from the tile surface interfering with the wetting of the tile by the epoxy resin, allowing faster em ulsification of it and generally easier clean-up.

Tall oil fatty acid can be substituted for tri-n-butyl phosphate and equivalent results are obtained.

EXAMPLE IV Tile grouts made using a dry Portland cement based composition and a liquid Latex additive give good performance properties but are difficult to install and EXAMPLE v Various Latex-Portland cement mortars were pre pared using liquid latex components presently available and commercially used for such compositions. These latex-portland cement grouts are designated A. B, C and D in the table below representing four different marketed brands of latex components used. The grout compositions were prepared to the desired consistency for grouting wall tile comprising about 40 parts by weight latex emulsion.

Each grout was spread over a separate tile area and into the vertical and horizOntal joints between the tiles by using a smooth, rubber trowel. After the joints were filled, the excess grout was removed by using the edge of the trowel as a squeegee.

Part A Control Each grout was allowed to set and dry for a short period of time and then the remaining grout film and excess material filling the joints was wetted with a sponge and water and scrubbed lightly. Extreme care was taken to avoid too much water which would run down the vertical joints between tile and wash away grout that should remain. The sponge was used to wet polish the tile surface and dress the joints to a smooth finish andeven contour. When the wall looked clean, sponging was stopped and the wall left to dry before final cleanup. As the wall dried a haze formed over the tile surfaces. The haze that formed could not easily be removed by the normal polishing procedure of cloth buffing. The haze adhered to the surfaces requiring hard and excessive polishing while necessitating extreme care to protect the grout in the joints.

After the haze was removed, the finished wall looked fine, but on close inspection it could be seen that vertical grout joints were deeper than ideal, for the grout suffered a condition called washed-out by the trade and the horizontal joints had creases in their center line in many instances. The whole operation took 25 minutes of working time and was tiring during the difficult polishing stages.

Part B Improving Materials The procedure described in Part A was repeated except that various improving materials were applied to the wall at a critical time.

After each grout was spread on the wall and forced into the joints, the wall was squeegeed as before. At this point in the operation a solution of improving material was sprayed on each wall area in sufficient quantity to just wet the grout and tile surfaces without causing the solution to run down the wall surface. Immediately after the spraying, the sponging and dressing of the joints was accomplished.

The Table below summarizes the effectiveness of each improving material used with the various latexportland cement grout compositions on the key properties of l firming of the grout in the joint and the (2) dustability of the haze which is important for clean efficient polishing.

LatexPortland Cement Grouts Property Improving Effect on Grout Material in Aqueous Continued Latex-Po rtland Cement Grouts Property Improving Effect on Grout Material in Aqueous In the Table A, B and C denote styrene-butadiene copolymer latex-portland cement groutscontaining as the latex component TEC Crete manufactured by Technical Adhesives, L & M flexible grout additive manufac-' tured by L & M Surco Mfg, Inc., and Laticrete No. 3701 grout additive manufactured by the US. Rubber Co., respectively. D, in the Table, is a polyvinyl acetate based latex-portland cement grout containing as the latex component TEC Tile Bond manufactured by Technical Adhesives.

It can be seen from the table that the property improving materials are not equally effective when used with each grout. For example, lower molecular weight polyacrylic acid (M.W. av. 8,000) used in small quantity was not found effective for grouts A and B although it was effective for C. When used at greater concentration, this low molecular weight polyacrylic acid was effective for all the grouts tested, namely, A, B and C. Also, anionic and nonionic polyacrylamides were found particularly effective for the D grout and not for the A grout. However, the cationic polyacrylamides were found effective for the A grout and not the D grout. With applicants present invention it is now possible for one skilled in the art to chose the property improving material most effective for a particular latexportland cement grout to obtain superior properties.

What is claimed is:

- 1. In a method of grouting tile which comprises the steps of:

a. trowelling a Latex-Portland cement grouting composition on a tiled substrate and into the joints between the tile, said tile placed on said substrate;

b. removing excess grout from the tile faces;

c washing the tile surface and shaping the joints to the desired configuration; and

d. cleaning the tile once the tile faces are dry; the improvement which comprises an additional step of applying to the grout after trowelling a material selected from the group consisting of polyacrylic acid, polyacrylamide, and water soluble phosphates which beneficially change the rheology of the grout subsequent to its placement between tiles.

2. The method of claim 1 wherein said material'is a polyacrylamide selected from the group consisting of anionic, cationic, and nonionic polyacrylamides, and mixtures thereof.

3. The method of claim 2 wherein the polyacrylamide is anionic in character.

4. The method of claim 2 wherein the polyacrylamide is cationic in character.

5. The method of claim 2 wherein the polyacrylamide is nonionic in character.

6. The method of claim 2 wherein the polyacrylamide is present in an aqueous solution in the range of 0.02 to 0.1 percent by weight of the solution.

7. The method of claim 1 wherein said material is a water-soluble phosphate.

8. The method of claim 7 wherein the water-soluble phosphate is a water soluble dibasic phosphate.

9. The method of claim 7 wherein the water-soluble phosphate is present in aqueous solution in the range of from ll2 percent by weight of the solution.

10. In a method of grouting tile which comprises the steps of:

a, trowelling a Latex-Portland cement grouting composition on a tiled substrate and into the joints between the tile, said tile placed on said substrate;

b. removing excess grout from the tile faces;

c. washing the tile surface and shaping the joints to the desired configuration; and

d. cleaning the tile once the tile faces are dry; the improvement which comprises an additional step of applying to the grout after trowelling polyacrylic acid which beneficially changes the rheology of the grout subsequent to its placement between tiles.

11. The method of claim 10 wherein the polyacrylic acid is present in an aqueous solution in amounts of from 0.5 percent to 5 percent by weight of the solution.

12. The method of claim 10 wherein the polyacrylic acid has a molecular weight of from 8,000 20,000.

l3.'The method of claim 10 wherein the polyacrylic acid has a molecular weight of from 16,000 to 20,000.

14. The method of claim 1 wherein the latex component of the latex-portland cement grouting composition comprises a styrene-butadiene copolymer.

15. The method of claim 1 wherein the latex portion of the latexortland grouting composition comprises polyvinyl acetate.

16,. The method of claim 1 wherein said beneficial changes comprise a sufficient firming of the grout so that when the washing or cleaning step is performed the grouting composition is not undesirably removed and- /or the forming of a dustable haze which is easily removed. 

1. IN A METHOD OF GROUTING TILE WHICH COMPRISES THE STEPS OF: A. TROWELLING A LATEX-PORTLAND CEMENT GROUTING COMPOSITION ON A TILED SUBSTRATE AND INTO THE JOINTS BETWEEN THE TILE, SAID TILE PLACED ON SAID SUBSTRATE; B. REMOVING EXCESS GROUT FROM THE TILE FACES; C. WASHING THE TILE SURFACE AND SHAPING THE JOINTS TO THE DESIRED CONFIGURATION; AND D. CLEANING THE TILE ONCE THE TILE FACES ARE DRY; THE IMPROVEMENT WHICH COMPRISES AN ADDITIONAL STEP OF APPLYING TO THE GROUT AFTER TROWELLING A MATERIAL SELECTED FROM THE GROUP CONSISTING OF POLYACRYLIC ACID, POLYACRYLAMIDE, AND WATER SOLUBLE PHOSPHATES WHICH BENEFICIALLY CHANGE THE RHEOLOGY OF THE GROUT SUBSEQUENT TO ITS PLACEMRNT BETWEEN TILES.
 2. The method of claim 1 wherein said material is a polyacrylamide selected from the group consisting of anionic, cationic, and nonionic polyacrylamides, and mixtures thereof.
 3. The method of claim 2 wherein the polyacrylamide is anionic in character.
 4. The method of claim 2 wherein the polyacrylamide is cationic in character.
 5. The method of claim 2 wherein the polyacrylamide is nonionic in character.
 6. The method of claim 2 wherein the polyacrylamide is present in an aqueous solution in the range of 0.02 to 0.1 percent by weight of the solution.
 7. The method of claim 1 wherein said material is a water-soluble phosphate.
 8. The method of claim 7 wherein the water-soluble phosphate is a water soluble dibasic phosphate.
 9. The method of claim 7 wherein the water-soluble phosphate is present in aqueous solution in the range of from 1-12 percent by weight of the solution.
 10. In a method of grouting tile which comprises the steps of: a. trowelling a Latex-Portland cement grouting composition on a tiled substrate and into the joints between the tile, said tile placed on said substrate; b. removing excess grout from the tile faces; c. washing the tile surface and shaping the joints to the desired configuration; and d. cleaning the tile once the tile faces are dry; the improvement which comprises an additional step of applying to the grout after trowelling polyacrylic acid which beneficially changes the rheology of the grout subsequent to its placement between tiles.
 11. The method of claim 10 wherein the polyacrylic acid is present in an aqueous solution in amounts of from 0.5 percent to 5 percent by weight of the solution.
 12. The method of claim 10 wherein the polyacrylic acid has a molecular weight of from 8,000 - 20,000.
 13. The method of claim 10 wherein the polyacrylic acid has a molecular weight of from 16,000 to 20,000.
 14. The method of claim 1 wherein the latex component of the latex-portland cement grouting composition comprises a styrene-butadiene copolymer.
 15. The method of claim 1 wherein the latex portion of the latex-portland grouting composition comprises polyvinyl acetate.
 16. The method of claim 1 wherein said beneficial changes comprise a sufficient firming of the grout so that when the washing or cleaning step is performed the grouting composition is not undesirably removed and/or the forming of a dustable haze which is easily removed. 